Locking means for electrical apparatus



March 3,. 1931. WANAMAKER 1194.876

LOCKING. MEANS FOR' ELECTRICAL APPARATUS Filgd Dec. 10 1924 Z/gwad" 3 6M Patented Mar. 3, 1931 UNITED STATES PATENT oFFicE ERNEST WANAMAKER, OF CHICAGO, ILLINOIS, ASSIGNOR TO KULP THEFTPROOF LAMP COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS LOOKING MEANSFOR ELECTRICAL APPARATUS Application filed December 10, 1924. Serial No. 754,897.

This invention relates to locking means or devices for locking electrical apparatus within supporting sockets and has particular reference to devices of this character for rendering electric lamp bulbs, plug fuses, and the like, theftproof.

The subject matter of this invention comprises an improvement over the device disclosed in the patent to D. R. Coughlin, Reissue Number 15,836,' dated May 13, 1924:, which discloses a theftproof electric lamp so made that it may be inserted in a socket of the usual construction and yet which cannot be stolen or removed from the socket until after the lamp bulb or electrical apparatus has become broken and displaced.

The objects of this invention include the provision of a very simple, durable and inexpensive construction for the purposes desired, such construction embodying substantially the minimum number of parts and being dependable and certain in its operation.

In the accompanying drawing, which illustrates one embodiment of my invention, Figure 1 is an elevational view illustrating an assembled lamp embodying my invention; Figure 2 is a central sectional View through the base of a lamp embodying this invention and showing the parts in assembled relationship, and Figure 3 is a detailed sectionalview of a portion of the lamp base member and shell contact.

In general, the invention as illustrated may comprise anelectric lamp bulb, 10, of standard construction, a base member, 11, adapted to be securely cemented upon the stem or neck, 12, of the lamp bulb and a threaded shell contact, 13, for embracing the base member, 11.

It will be understood that I do not desire to restrict the application of my invention to its use with lamp bulbs, since various other types of electrical apparatus, such as plug fuses, thermo-ionic valves, and the like, may be substituted for the lamp bulb, 10, and rendered theftproof in accordance with this invention.

The base member, 11, may comprise a cylindrical shell contact, 14, vupon which the threaded shell :contact, 13, is loosely fitted.

The shell contact, 14, may be provided with one or more pin or rivet members as at 15,

which may engage or extend through the shell contact, 13, for the purpose of initially fixing the shell contact against rotation rela- I tive to the lamp base and lamp.

It will be observed that when the base member, 11, is rotated as by grasping the bulb 10. for inserting the lamp into a receptacle, the shell contact, 13, will also be rotated because of the-rivet connection, 15. In thismanner,"

base member 11 and, accordingly, when an attempt is made to remove the lamp from its receptacle by turning the bulb the base member, 11, will merely freely rotate within the threaded shell contact and without exerting rotational force upon such contact. Hence, thebulb or other apparatus, together withthe base member, .11, will be merely rotated and cannotvbe removed.

' 3. Thereafter, the shell contact 13 will be 7 free for rotational movement in respect to the After the lamp or other electrical appa.ra- I tus has become Wornout so that it is desirable to remove the same, the operator may place a canvas orv other bag over the glass portion of the lamp and thereupon break the lamp. The canvas bag Will retain the particles ofbroken glass. Access may then be had to a flanged edge, 16, on the threaded shell contact for removal thereof by the use. of pliers or other suitable tools.

The threaded shell contact, 13, may be permanently retained against longitudinal movement in respect to the lamp by means of the flange, 16, at therlower edge of the con- I tact and'a flange, 17 at the upper edge or end thereof. The flange, 16, is adapted to be spun over and to abut a beaded portion, 18, formed upon'the base'member near its lower edge. The flange, 17, is adapted to be From an inspection of Figure 2, it will be observed that the lower portions of the flange, 16, may be located at a point which will be well withinthe receptacle member in which the lamp may be inserted. in this way, the receptacle member serves to prevent access to the threaded shell contact member andaccordingly this member cannot be turned either inwardly or out not the receptacle by tampering while the "lamp or other electrical apparatus is in operative condition.

As shown in Figure 2, the interior of the base member, 11, may Ebe :filled with a suitable cement :to cement the base member to the neck of the bulb in the conventional manner. At :the'upper end of the base member, 11, a center contact, 20, may be positioned and held inpplace bythe use of an'insulating end piece, 21,1Which maybe tightly fitted or molded into the upper end of the base meniber, l'l. Lead wires, 22 and 23, tromthe lamp filament :or other electrical devices 'may be electrically-connected to the contacts, 13 and 20, respectively, in *any suitable and well known manner.

It Willbe noted 'that the rivet or pinineinber, 15, as illustrated, isot small cross-section=so that it may :be readily sheared by the :relative rotation of the base member and the contact, 13. The exact dimensions A section of soft iron wire has been found headed, as lDdlCELt-GCl,lll'l' order to prevent them" from drawingthrough the perforations before-"the shea'ringvaction takesapl'ace. After the shearing action has been eitected,"the

outer end of'the rivet "may drop out, as in- I V a v rca e m I '1 1T6 'vner as e l ner e1 0 d t d 1 gr 3, v e ti r1 ll 'oi the rivet will remain within the beaded portion, 18. The shearing action is such that the -rivetwill be sheared along a predetermined'line andwith ansmooth cut. The sheared ends'ofthe rivet hence will there- 'afterofier no resistance-to the ireeturning o i r the threaded shell contact.

While I have described my improvements inxdetailand in connection with apreterred form thereo'ffl do not desire to'be limited to suchdetails or form, since many changes and 'modifications maybe made and the invention embodied in 'various diiierent forms without departing fromthesp'irit and scope of "the :invention in its broader aspects. Therefore, I desire to cover all modifications and forms coming within the language or scope of any one or more of the appended claims.

I-laving thus described my invention, what I claim as new and desire to secure by Let ters Patent ofthe United States is:

1. An electric lamp comprising a bulb, and a shell-contact and an insulated center contact therefor, means fixing the shell contact against "longitudinal movement in respect to said-bulb'menibenarivet initially fixing said .bnlb against rotation inrrespect to said shell contact and purposely designed to be sheared by the exert-ionof a predetermined force to effect such rotation, a filament in said bulb, and means for maintainingelectrical connection between said filament and said shell and center contacts regardless-of the rotation of the bulb member with'respectltoitheshell contact. v

2. In an electric lamp, a bulb ,.a center contact and a shell contact therefor, vmetallic means for initiallysecuring the bulb against rotation in respect to said shell contact, said means being'purposely designedto-besheared forpermittin the bulb to 'be independently rotatable after the exertion of a predetermined force to eflect independent rotation thereof, and meanstor maintainingelectrical connection between thelampifilament and the shel and centercontacts-regardless otithe rotation of the bulb.

3. In tleft-proofelectriclamp, bulb, a center contactand a-shellcontact therefor, the shell contactbeing screw threaded forengagement" with the conventional socket and also provided with metallic-means for securing the bulb against rotation :in respect to saidshell contact while the lamp is being inserted into a socket, said metallic means beingpurpeselydesigned to be sheared along a predetermined linev for releasingtthe .bulb in respect to .the-shellcontact after the exertion of abnormal'force to efiectindependent rotation thereof.

l. In combination; an enclosure for electrical apparatus, a cylindrical shell mounted on said enclosure, means for preventing -.unauthorized removal ofthe enclosure fromi'the SllSlL'fSflddjShGll being provided with means tor engaginga supportingreceptacle ibyturn 111g movement of said shell, and riveting means initiallyfixing said enclosure against rotation in respect tosaidshellztonormally permit insertion and removal of'the-shell in respect to a receptacle by turning :said enclosure,-said riveting means being purposely designed tolbe disengaged by the exertion of a predetermined iorce to (effect "rfurther inward turning of" the enclosure in irespect to the receptacle.

5. Iii-combination anelectric lamp bulb member provided with a substantially cylindrical supporting shell, said shell: being provided with rmeans for engaging a supporting receptacle by turning movement of said shell, rivet means for securing said shell to the bulb member and against rotation in either direction whereby the lamp may be used in the ordinary way if desired, but said rivet means being purposely designed tobecome disengaged for permitting said bulb to be rotatable in respect to said shell after being subjected to an abnormal rotational force tending to turn the lamp into a socket, where by the lamp is made theft-proof and cannot be thereafter turned out of the socket until the bulb is broken to expose portions of said shell.

6. In combination, an electric lamp bulb provided with a shell contact, means including a pin for mounting thereon the shell contact to be initially fixed against rotation in either direction in respect thereto, said means being purposely designed for permitting said bulb to be freely rotatable in respect to sa1d contact in either direction after being subjected to a predetermined disrupting force, andmeans for supplying electrical energy to the lamp through said shell contact after such rotation of the bulb.

7. In combination an electric lamp bulb provided with a substantially cylindrical supporting shell, said shell bemg provided with means for engaging a supportlng receptacle by turning movement of said shell, means including a pin for mounting said shell on the bulb to be initially fixed agalnst rotation in either direction in respect thereto, said pm being purposely designed for permitting sa1d bulb to be rotatable'in respect to sa1d shell in either direction after being subjected to a predetermined force to disengage sa1d pm, and means for preventing removal of the bulb from the shell.

8. An incandescent lamp consisting of a bulb, and center and shell contacts therefor, the shell contact being screw-threaded 1n the conventional manner and also provided w1th inwardly protruding metallic means to secure the shell contact in respect tothe bulb so as to permit of the lamp being screwed I into a socket by simple rotation of the bulb, sa1d metallic means being purposely deslgned to be, deranged and released by the application ofan abnormal force to effect rotation of the bulb after the lampis screwed home sothat the bulb will then rotate independently of the shell contact, and means for maintaining electrical connection between the lamp filament and the contacts notwithstanding such indethe peripheral edges of said threaded contact being turned inwardly and said metallic shell being formed with a beaded portion cooperating with one of said inwardly turned edges to feet further inward turning of the bulb in respect" to a receptacle.

10. In-combination an electric lamp bulb, a substantially cylindrical supporting and contact carrying member permanently cemented thereto, a threaded shell contact embracing said member and rivet means adjacent the peripheral edge nearest the body of the bulb on said contact for initially fixing said bulb against rotation in respect to said contact to normally pernnt insertion and removal of the threaded shell in respect to a receptacle,v

by turning said bulb, but said rivet means being purposely designed tobe disengaged by the exertion of an abnormal force to effect further inward turning of the shell in respect to a receptacle. f

11. A theft-proof base for electric lamps,

comprising an inner shell, an outer screwthreaded shell surrounding the inner shell, means to prevent relative longitudinal movement of the two shells, and a frangible pin ex- I tendingthroughthe two shells and serving to cause the conjoint movement of the two shells in the act of screwing the base into a usual lampsocket and breaking upon further turmng of the base in the same direction and thereby preventing the rotation of the screwthreaded shell.

12. theft-proof base for electric lamps, comprising an inner shell in which a lamp bulb is adapted to be fixed, an outer screwthreaded shell surrounding the inner shell, means to prevent relative longitudinal movement of the two shells, the two shells having al gned perforations, and a frangible pin applied transversely to the two shells through their perforations and fixed therein and connecting the two shells against relative rotary movement and adapting them to turn together to an extent sufficient to permit the seating of the lamp in the socket and thereafter upon further turning of the lamp in the same direction being broken thereby preventing the rotation of the screw-threaded shell and consequently the removal of the lamp intact.

13. A theft-proof base for electric lamps, comprising an inner shell having a circumferential bead provided with a transverse perforation and an outer shell having a transverse perforation, said shellsarranged one within the other, means on the outer shell engaging the inner shell to prevent relative longitudinal movement of the-two shel;ls,and a frangible connection for the shellsapplied in the perforated bead and in vthe perforation ofthe outer shell and adapted topermitthe insertion of the lamp ina socket and by further movement in the same direction to sever the connection and thereby prevent removal of the lamp intact. V

14:. A theftproof base for electric lamps,

comprising an inner shell, a shellsurrounding the inner shell,;means -to prevent relati ve longitudinal movement of the twoshells, including a frangible pin extending ,through the two shells and serving to cause the conjoint movement of the two shells in the act ofscrewing the base into a usual ,lam psockct and breaking upon further turning of the base in the same direction, and (thereby preventing the rotation of thetsecondunentioned shell.

15. A theftproof base for electric lamps, comprising an inner annular member secured to the lamp, a shell surrounding ;the inner member screw-threaded for engagement with the usual electric lamp socket, meansto prevent relative longitudinal displacement of,

the shell and inner member, a transversely positioned frangible pin cooperatively associated With the inner member and the outer screw-threaded shell and serving to cause the conjoint movement of the two shells in the act of screwing the base into the usual lamp socket, and breaking upon further turning of the base in the same direction and thereby preventing the rotation of the sc rewthreaded shell.

In witness whereof, I have hereunto subscribed my name.

ERNEST WANAMA'KEB. 

